1. Field of the Invention
The present invention is in the field of food packages and is directed more specifically to a tamperproof food package which may be readily opened for use and reclosed, if necessary, after partial consumption of the contents.
2. The Prior Art
It is conventional for dispensing in vending machines, in catered cafeteria services and in like applications to provide a transparent package formed of polymeric material and provided with a lid or covering member frictionally mounted in closing relation of the package. Packages of the type described are also frequently used in connection with the sale of candy items, etc.
It has been proposed to form packages of the type described with a covering sheet, specifically of heat sealable plastic bonded both to the cover and to a rim of the package or receptacle, devices of the latter type being shown, by way of example, in my U.S. Pat. No. 4,346,833 and in certain of the references cited therein. Provision of a sealing membrane provides the consumer with a high degree of assurance that the contents of the package have not been tampered with.
In packages of the sort illustrated in the above referenced patent, the cover is frictionally retained in position within the receptacle and a high degree of reliance for retaining the cover in the noted position is placed upon the fact that the membrane which is sealingly connected to the rim of the receptacle is likewise sealingly connected to a rim portion of the cover.
Constructions of the type described provide a high degree of security for the contents of the package until the membrane is removed. However, following removal of the membrane, if it is desired to reclose the package, frictional interengagement of the cover in the receptacle does not provide a dependable means for assuring that the package will remain reclosed.
By way of example, any crushing forces exerted on the package have the tendency to cause the cover to pop free. Also, any upward force exerted against the flange of such device would immediately unseat the cover.
Additionally, constructions of the type set forth involve the sealing of the membrane to coplanar surfaces of the package rim and cover flange.
Such constructions are of necessity of relatively limited structural strength, with the result that when laterally exerted compressive forces are applied to the container, following removal of the membrane, there is little resistance to deformation of the container.
Still a further disadvantage of containers of the type described resides in the fact that elements or increments of the membrane remain bonded to the cover after the cover has been removed, presenting a ragged appearance.
Finally, the separation of the cover of such known containers, upon initial opening of the package presents certain difficulties since the formation of an effective seal of the membrane to both cover and container perimeters requires that these parts be closely juxtaposed, making it difficult for the purchaser to reach into the limited clearance spaces between the noted components and pry the cover free.